General CommentHe used to chase her room, something that happened in the physical world. But if they leave they wont have to cope or adhere to the stuff that people have to to get through the day, the arguments that people have...

These two have days and a life that isnt numbered or timed.

everything that happens, the screaming grass, the midnight cars, the chasing, honey dripping, drinking ,the bodies under the floor-death, all the things that shouldnt be happening.
they just leave it all behind.

General CommentThis is just an idea but some of the words in the song have kind of evoked a story in my mind... Is it possible he's talking about an accidental pregnancy that is turning their summer fling sour('beauty's gone all sore')? They are counting the days on their fingers from her last period and maybe the day they made love, and they thought they were safe but they got it wrong because they were so in love the hot summer days appeared to all be melting into each other. ('If we got it wrong, it's because the days have no numbers'). Now he's thinking about running away together.
As I said, just an idea, and it doesn't explain everything in the song, for example, I have no idea what 'honey dripping pale of skin while there's bodies underneath the floor' is supposed to mean. :-)